I bought an Armalite M15A4 specifically for 3-gun. Initially equipped with a Leupold 1.5-5x20mm.

I eventually had the factory barrel swapped for a JP, and got a smoking deal on a used JP free-float tube (thanks Zak). Dropped in a Chip McCormick single-stage trigger. Swapped out the pistol-grip. Eventually went to a TA11 ACOG & LaRue mount. There's a surprising amount of money tied up in that gun.

Bought an Olympic K9GL. Factory floated barrel and SIR quad-rails. Trijicon Accupoint in an Armalite 1pc mount. Magpul M93B stock. BUIS, VFG, etc. Again -- wow -- amazing what it adds up to.

So I've got essentially a Cavalry Arms "Trooper". 1:9" twist, 14.5" with the permanently attached flash-suppressor. I selected this in part because I COULDN'T screw with it.

I've managed to last 7 months.

Now I keep finding myself thinking about a fairly heavy 1:8" twist, stainless barrel. Probably 16", plus a flash-suppressor. As long a gas-system as I can get (never seen / heard of rifle-length on a 16"). Maybe a LaRue 13.2" handguard. Surefire.

Or maybe go SBR.

Mike